Findings indicate that (1) development of probability reasoning can be shown by an increasing monotonic trend with age, (2) verbal tests assess different aspects of this development than do nonverbal tests, (3) Piaget's ontogenetic age brackets are accurate, and (4) sex and intelligence are not significant variables. (MH)

The performance of 40 hearing and 40 hearing-impaired children, aged two-five years, was compared on a battery of nonverbal tasks and a nonverbal intelligence test. Age significantly affected the results, consistent with a developmental change. In cognitive development, the hearing-impaired children were comparable to same-age hearing children.…

Eighty subjects 4, 6, 8, and 10 years of age inductively identified partially uncovered silhouettes of three simple pictures. Subjects removed as few as possible covering pieces, according to their own strategies, to correctly name the pictures. Performance generally improved with increased age on the two dependent measures, inductively inferring…